Let's say I have a docker-compose file with two containers:
version: "3"
services:
app:
image: someimage:fpm-alpine
volumes:
- myvolume:/var/www/html
web:
image: nginx:alpine
volumes:
- myvolume:/var/www/html
volumes:
myvolume:
The app container contains the application code in the /var/www/html directory which gets updated with each version of the image, so I don't want this directory to be persistent.
Yet I need to share the data with the nginx container. If I use a volume or a host bind the data is persistent and doesn't get updated with a new version. Maybe there is a way to automatically delete a volume whenever I pull a new image? Or a way to share an anonymous volume?
i think its better for you to use anonymous volume
volumes:
- ./:/var/www/html
You would have to be willing to drop back to docker-compose version 2 and use data containers with the volumes_from directive.
Which is equivalent to --volumes-from on a docker run command.
This should work fine. The problem isn't with docker. You can use volumes to communicate in this way. If you run docker-compose up in a directory with the following compose file:
version: "3"
services:
one:
image: ubuntu
command: sleep 100000
volumes:
- vol:/vol
two:
image: ubuntu
command: sleep 100000
volumes:
- vol:/vol
volumes:
vol:
Then, in a 2nd terminal docker exec -it so_one_1 bash (you might have to do a docker ps to find the exact name of the container, it can change). You'll find yourself in a bash container. Change to the /vol directory cd /vol and then echo "wobble" > wibble.txt", then exit` the shell (ctrl-d).
In the same terminal you can then type docker exec -it so_two_1 bash (again, check the names). Just like last time you can cd /vol and type ls -gAlFh you'll see the wibble.txt file we created in the other container. You can even cat wibble.txt to see the contents. It'll be there.
So if the problem isn't docker, what can it be? I think the problem is that nginx isn't seeing the changes on the filesystem. For that, I believe that setting expires -1; inside a location block in the config will actually disable caching completely and may solve the problem (dev only).
Related
I've been trying to accomplish migrating a volume from one container to the same container on a different host, just by testing out the method in the Docker docs: Restore Volume from Backup. However, the project I am working on starts the container using docker-compose instead of docker run. Anyone know if I can change the .yaml file somehow to decompress a tarball (similar to the docker run method)?
The docker run command for restoring from a backup looks like this:
docker run --rm --volumes-from dbstore2 -v $(pwd):/backup ubuntu bash -c "cd /dbdata && tar xvf /backup/backup.tar --strip 1"
If you can decompress the tarball file you can use this in your docker-compose.yaml file
mysql:
image: mysql:5.7
hostname: mysql
container_name: mysql
restart: always
expose:
- '3306'
ports:
- '3306:3306'
environment:
- 'MYSQL_ROOT_PASSWORD=something'
volumes:
- mysql_db:/var/lib/mysql
- ./your-backup.sql-file:/docker-entrypoint-initdb.d
So, I followed the docs linked in my question. The reason it wasn't working originally is because I needed to double check that the original volume AND container were removed before mounting the backup volume.
Essentially,
Backup volume as per the Docker documentation
Remove original container and volume
Restore volume as per documentation
I am very (read very) new to Docker so experimenting. I have created a very basic Dockerfile to pull in Laravel:
FROM composer:latest
RUN composer_version="$(composer --version)" && echo $composer_version
RUN composer global require laravel/installer
WORKDIR /var/www
RUN composer create-project --prefer-dist laravel/laravel site
My docker-compose.yml file looks like:
version: '3.7'
services:
laravel:
build:
context: .
dockerfile: laravel.dockerfile
container_name: my_laravel
network_mode: host
restart: on-failure
volumes:
- ./site:/var/www/site
When I run docker-compose up, the ./site directory is created but the contents are empty. I've put this in docker-compose as I plan on on including other things like nginx, mysql, php etc
The command:
docker run -v "/where/i/want/data/site:/var/www/site" my_laravel
Results in the same behaviour.
I know the install is successful as I modified my dockerfile with the follwing two lines appended to it:
WORKDIR /var/www/site
RUN ls -la
Which gives me the correct listing.
Clearly misunderstanding something here. Any help appreciated.
EDIT: So, I was able to get this to work... although, it slightly more difficult than just specifying a path..
You can accomplish this by specifying a volume in docker-compose.yml.. The path to the directory (on the host) is labeled as device in the compose file.. It appears that the root of the path has to be an actual volume (possibly a share would work) but the 'destination' of the path can be a directory on the specified volume..
I created a new volume called docker on my machine but I suppose you could do this with your existing disk/volume..
I am on a Mac and this docker-compose.yml file worked for me:
version: '3.7'
services:
nodemon-test:
container_name: my-nodemon-test
image: oze4/nodemon-docker-test
ports:
- "1337:1337"
volumes:
- docker_test_app:/app # see comment below on which name to use here
volumes:
docker_test_app: # use this name under `volumes:` for the service
name: docker_test_app
driver: local
driver_opts:
o: bind
type: none
device: /Volumes/docker/docker_test_app
The container specified exists in my DockerHub.. this is the source code for it, just in case you are worried about anything malicious. I created it like two weeks ago to help someone else on StackOverflow.
Shows files from the container on my machine (the host)..
You can read more about Docker Volume configs here if you would like.
ORIGINAL ANSWER:
It looks like you are trying to share the build directory with your host machine.. After some testing, it appears Docker will overwrite the specified path on the container with the contents of the path on the host.
If you run docker logs my_laravel you should see an error about missing files at /var/www/site.. So, even though the build is successful - once Docker mounts the directory from your machine (./site) onto the container (/var/www/site) it overwrites the path within the container (/var/www/site) with the contents of the path on your host (./site) - which is empty.
To test and make sure the contents of /var/www/site are in fact being overwritten, you can run docker exec -it /bin/bash (you may need to replace /bin/bash with /bash).. This will give you command line access inside of the container. From there you can do ls -a /var/www/site..
Furthermore, you can also pre-stage ./site to have a random test file in it (test.txt or whatever), then docker-compose up -d, then run the same commands from the step above docker exec -it ... and see if the staged test.txt file is now inside the container - this gives you definitive evidence that when you run volumes, the data on your host overwrites data in the container.
With that being said, doing something like this and sharing a log directory will work... the volume path specified on the container is still overwritten, the difference is the container is writing to that path.. it doesn't rely on it for config files/app files.
Hope this helps.
Here is a simplified version of my docker-compose.yml (it's the volume in buggy-service that does not behave as I expect):
version: '3.4'
services:
local-db:
image: postgres:9.6
environment:
- DB_NAME=${DB_NAME}
# other env vars (not important)
ports:
- 5432:5432
volumes:
- ~/.docker-volumes/${DB_NAME}/postgresql/data:/var/lib/postgresql/data
- postgresql:/docker-entrypoint-initdb.d
buggy-service:
build:
context: .
dockerfile: Dockerfile.test
target: buggy-image
args:
# bunch of args (not important)
volumes:
- /Users/me/temp:/temp
volumes:
postgresql:
driver_opts:
type: none
device: /Users/me/postgresql
o: bind
If I do docker-compose -f docker-compose.yml up -d local-db, a container for it starts up automatically and I find that /Users/me/postgresql on the host machine (Mac OSX) binds correctly to /docker-entrypoint-initdb.d with content synced.
However, if I do docker-compose -f docker-compose.yml up --build -d buggy-service, a container does not start up automatically.
Question: How do I get buggy-service to behave like local-db, i.e., start up automatically with the required volume mounted?
Here's the stripped down version of Dockerfile.test referenced by buggy-service:
FROM microsoft/dotnet:2.1-sdk-alpine AS buggy-image
# Bunch of ARG definitions (not important)
VOLUME /temp
# other stuff (not important)
ENTRYPOINT ["/bin/bash"]
# Other FROMs
Edit 1
A bit more info about what I’m trying to achieve...
The buggy-container I’m trying to get working runs .Net Core as the base image. Its purpose is to run dotnet test and generate coverage reports, which can then be consumed in the host, which may either be a local dev machine or a build server (in this case, BitBucket pipelines).
... followed by docker run -dit --name buggy-container buggy-image
This command creates a new container, not based on anything in the compose yml file. Without a volume specification, it will only get an anonymous volume since you've defined the volume in the Dockerfile (I tend to recommend against defining a volume there). You can see the anonymous volumes with a docker volume ls command, they'll be the ones with a long unique id and no reference to what they belong to.
To define a host volume from docker run, you need the -v flag:
docker run -dit -v /Users/me/temp:/temp --name buggy-container buggy-image
From your now changed question, you have a new issue. Your container specifies a single command to run in the entrypoint:
ENTRYPOINT ["/bin/bash"]
When bash runs, it reads input from stdin. When that input ends, like when you run a container with no input attached, bash will exit. When the process your container runs exits, the container exits. From the details available, I can't tell you what that command should be, but a good starting point is to look at other images on docker hub that perform a similar task that you're trying to run, and look at the Dockerfile they use (many hub images point back to a GitHub repo with the full source).
Until now, I have used a local LAMP stack to develop my web projects and deploy them manually to the server. For the next project I want to use docker and docker-compose to create a mariaDB, NGINX and a project container for easy developing and deploying.
When developing I want my code directory on the host machine to be synchronised with the docker container. I know that could be achieved by running
docker run -dt --name containerName -v /path/on/host:/path/in/container
in the cli as stated here, but I want to do that within a docker-compose v2 file.
I am as far as having a docker-composer.yml file looking like this:
version: '2'
services:
db:
#[...]
myProj:
build: ./myProj
image: myProj
depends_on:
- db
volumes:
myCodeVolume:/var/www
volumes:
myCodeVolume:
How can I synchronise my /var/www directory in the container with my host machine (Ubuntu desktop, macos or Windows machine)?
Thank you for your help.
It is pretty much the same way, you do the host:container mapping directly under the services.myProj.volumes key in your compose file:
version: '2'
services:
...
myProj:
...
volumes:
/path/to/file/on/host:/var/www
Note that the top-level volumes key is removed.
This file could be translated into:
docker create --links db -v /path/to/file/on/host:/var/www myProj
When docker-compose finds the top-level volumes section it tries to docker volume create the keys under it first before creating any other container. Those volumes could be then used to hold the data you want to be persistent across containers.
So, if I take your file for an example, it would translate into something like this:
docker volume create myCodeVolume
docker create --links db -v myCodeVoume:/var/www myProj
docker-compose:
mysql:
image: mysql:5.7.16
container_name: f_mysql
volumes:
- ./db:/var/lib/mysql
environment:
MYSQL_ROOT_PASSWORD: sheep
expose:
- '3306'
and I use docker exec input this container,
and I type echo $MYSQL_ROOT_PASSWORD, then I got sheep,
but the mysql root password still is '',
when I type 'mysql -uroot', I login mysql.
For me the issue was that I'd created the db volume with the random password option set, then disabled that, but hadn't cleared the volume. So no matter what changes I made to the docker-compose file, the old volume with the old login information was still there.
I had to docker volume ls to find the volume then docker volume rm <name> to remove it. After re-upping, everything worked.
Regarding other answers on this page, the format for specifying env variables is correct, you can use either
environment:
MYSQL_ROOT_PASSWORD: a_password
OR
environment:
- MYSQL_ROOT_PASSWORD=a_password
The image entrypoint script will never make changes to a database which is existing. If you mount an existing data directory into var/lib/mysql then MYSQL_ROOT_PASSWORD will have no effect.
Workaround
Remove all unused volumes: docker volume prune
Remove the volume from your database service: docker volume rm <db_data>
Down containers, remove volumes: docker-compose down --volumes
You need to fix your docker-compose file:
environment:
- MYSQL_ROOT_PASSWORD=sheep
The following is the full docker-compose that achieves what you want:
version: '2'
services:
mysql:
image: mysql:5.7.16
container_name: f_mysql
volumes:
- ./db:/var/lib/mysql
environment:
- MYSQL_ROOT_PASSWORD=sheep
expose:
- '3306'
Then with a docker exec -it f_mysql /bin/bash and inside the container mysql -u root -p, using sheep, as the password, will be the only way to connect to the mysql server.
This happens when your volume from a directory has wrong permission.
You can fix this letting docker to create directory itself.
In case you have an existent data, you can compare the new one with the previous one in order to apply correct chmod, because this depends on if docker/your-user is part of root group.
Please note that according to the official docker image: "none of those variables will have any effect if you start the container with a data directory that already contains a database". In fact, in this case, you have already a "mysql.user" table, and you should use the user info set there that there. The same thing happens when you try to restore a full dump.
This happened when the the mount directory has ea(extended attribute) on Mac.
It is better to delete the directory once and recreate it or check the permission with the xattr command.
$ ls -l ./db
$ xattr ls ./db
I had a same problem, and after a lot of try I found my solution. When I run first time the docker-composer, I left everything on the original settings like this:
environment:
MYSQL_ROOT_PASSWORD: MYSQL_ROOT_PASSWORD
Then I change the password, say "docker-compose up" but it was still MYSQL_ROOT_PASSWORD.
My solution was delete the "mysql" docker image from my disk. After that, the docker download everything again BUT also set my password for the root as well. Maybe this is not the best, but I am also a beginner in Docker.
So in nutshell the simple "docker-compose up" does not enough.